sperry



March 4, 1930, E. A. SPERRY 17,614

fiEACON SYSTEM FOR NIGHT FLYING Original Filed April 26, 1922 3 Sheets-Sheet l INVENTOR [2mm /7. SPEPR Y.

' MZYW ATTORNEY.

E. A. SPERRY BEACON SYSTEM FOR NIGHT FLYING March 4, 1930.

Original Filed April 26. 1922 3 Sheets-Sheet w A Q a m R M 3 ,M m m o/- W \y J ,1. j l. Z 5 7 2 pm 9 @6 ,wvw,l ,m M 4 7 L 6 pm NW 9 w M J v G M, 6 6 m w m w l M W l r w 4 7 m In MW I 7. 6 0 7 F J? 6 7 1 /V//////////////////A EEEIII 7 w J W March 4, 1930. sP R i Re. 17,614

BEACON SYSTEM FOR NIGHT FLYING Original Filed April 26, 1922 3 Sheets-Sheet 3 INVENTOR m a Pewfin )ZfoRNEJ.

Reissued Mar. 4, 1930 UNITED STATES PATENT OFFICE ELMEB A. SPERRY, OF BROOKLYN, NEW YORK, ASSIGNOR TO SPERRY DEVELOPMENT COMPANY, OF DOVER, DELAWARE, A CORPORATION OF DELAWARE BEACON SYSTEM FOR NIGHT FLYING Original application filed April 26, 1922, Serial No. 556,783.

Renewed November 11, 1927. Original No.

1,708,377, dated April 16, 1929. Application for reissue filed June 18, 1929. Serial No. 371,862.

This invention relates to a signaling system for guiding aircraft when flying at night or in thick weather when the usual landmarks are invisible. Said signals may be of a type by which the aviator may tell his position with reference .to any predetermined objective.

The object of the invention is to provide a system and means whereby an aviator traveling between distant points, may either automatically or at will successively bring into operation, a series of signals, lights or other beacons stationed at intervals along the course of travel, or whereby hemay selectively bring into operation the lights of any of several beacon stations or aviation fields over which he has control. For this purpose the landing fields are equipped with any form ofreceiving apparatus which is adapted to be brought into operation from a disturbanceproducing or wave impulse-producing means on the aircraft. As illustrating one form my invention may assume, I have shown a radio sending and receiving system, but it will be understood that other systems of producing and receiving impulses may be em ployed within the scope of the appended claims.

Referring to the drawings wherein I have shown what I now consider to be the preferred form of my invention:

Fig. 1 is a wiring diagram of a radio transmitting set adapted to be carried by the aircraft for controlling the beacons.

Fig. 2 is a diagrammatic representation of a beacon and the radio receiving and controlling apparatus therefor. I

Fig. 3 is a transmitter casing partly in section of a modified form of the invention.

Fig. 4 is a diagrammatic view of part of the apparatus contained in the casing shown in Fig. 3.

Fig. 5 is a diagrammatic view of abeacon and the receiving and controlling apparatus therefor, adapted in turn to be controlled by the apparatus shown in Figs. 3 and 4.

Figs. 6, 7 and 8 are details of a part of the selector system located at separate stations.

Fig. 9 shows several landing field lights controlled by my device.

electrode 6, causing a high potential discharge between the electrodes which is greatly aided by the condenser 10.

In Fig. 2 I have shown a simple receiving apparatus, comprising an antenna 13 connected through a primary winding 14 and a condenser 15 to the ground 16; a secondary 17 connected with a condenser 18, and an audion 19'. A source of energy for heating the filament of the audion is shown at 20. A

second source of energy 21 is shown conneetv .ed with the audion and with a relay 22. It

will be understood that an impulse emanating from the sending antenna 11 and received by the antenna 13 will through the action of the audion and the battery 21 cause energization of the relay 22.

The armature 23 of the relay is shown as adapted to close a circuit through a battery 24 or other suitable source of electrical energy and a solenoid 25 by engaging contact 26. The armature 27 of solenoid 25 may be connected to a lever 28 pivoted at 29 and adapted to engage a contact 30 at one end. The other end of said lever may carry a contact 31 adapted to engage a fixed contact 32. Said other end of lever 28 is shown as carrying a roller 33 adapted to fit into a notch 34 in a wheel 35. A spring 36 may be provided to press the roller into said notch 34. Wheel 35 is carried on a shaft 37 of reduction gearing 38 which is in turn actuated by a motor 39. Said motor is shown as connected by wires 40, 41'through a battery 42 to contacts 31, 32.

As the signaling means Ihave illustrated a Searchlight or beacon adapted to project a vertical beam although it will be understood that other forms of radiant signals, visible or otherwise, may be employed, if desired. The beacon itself is shown at A in diagrammatic form only, as the specific form of signal employed forms no part of this invention. For

a more complete disclosure of this type ofbeacon, reference is had to my patent for an aviation beacon No. 1,548,958, issued August 11, 1925. It will be understood that the usual automatic arc'lamp wherein the closing of a circuit will cause the lamp to light and remain lighted whilethe circuit is so closed may be employed such as shown in my U. S.

Patent No. 1562,57 5. The positive and negative electrodes of such a lamp are shown at 43, 4:4; in connection with a projector which may be so positioned as toproject a. beam of light upwardly into the sky. The electrodes are supported by holders 113, 114 mounted on an arm 115 secured to the control boX116 which contains mechanism for automatically controlling the electrodes through rods 117,

118. The supplylines are shown at 16,47,

the line 17 having interposed therein a switch comprising the aforementioned lever armi28 and contact 30. I

Each beacon station may be provided with. i the apparatus shown in Fig. 2. This apparatus may be adapted'to respond, by closing contacts 23, 26,to impulses of a predetermined wave length and amplitude. These adjustments may be effected by any of the well known methods; as for instance, by means of the variable condensers 15, 18. and' by varying the. amount of secondary 17, in cluded in the circuit. These adjustments having been effected may thereat'terbe maintained. Thesendingapparatuson the other hand, may if desired, be so adjusted as to be slightlydetuned to thereceiver, but provided with suflicient amplitude to cause the receiver to respond under normal weather con ditions when within a predetermined radius. When adverse weather conditions PIBXELil so that the impulses produced by the transmitter do not reach the receiver with suflicient amplitude to cause the latter'to respond, the aviator having cognizance of, the weather conditions, may compensate for the same by increasing the amplitude of the transmitter and at the same time tuning a little closer to operation a beacon. located, at a predeter I mined distance ahead of him. This may be done by closing key 8 when approaching the beacon. Or the key maybe kept closed as the aviator flies, thebeacon being lighted as soon as the transmitter. comes withinreach of the receiver. Where the system employed isto keepthe sendingh'eyS locked, the timing disc 35 may be omitted. The switch 28 30 will then be held closed by the continued action of solenoid 25 until the aircraft passes beyond the point where the impulses transmitted are able to control the receiver, whereupon thelight will cease to burn.

Another method by which the aviator may control the lightingof the several beacons may be by-tuning, each receiver such as shown in Fig. 2 to a different wave length. An aviator may be provided with a chart showing the positions of the several beacons and their wave lengths. When he desires to light a certain beacon, he will adjust his apparatus to produce oscillations of the wave length of that beacon and then press the sending key'S. The apparatus in Fig. 2 located at that beacon will respond. 1 p

, Obviously the apparatus should be tuned to wave lengths which are not commonly used in radio transmission, so that the beacons will not be lightedv by interfering sources. v

In order that the stations may be comparatively immune from interference, a system may be employed wherein the receiverswill not only be tuned to operate at a particular wave length but will only operate in response to that wave length when apredetermined code or combination of impulses or an impulse of a given duration isreceived. Each station may have its separate code and the transmitter may be adapted to automatically transmit the code of any station in response tothe actuation of a selector switch. While the system and thecodes may be made very complex, I have shown in Figs. 3 to 8 inclusive, a simple. form of selector system which will. serve to illustrate my invention.

In this form the same type ofsending ap paratus as disclosed in Fig. 1 is used for illustration in 4.. The: resistance 9, however, is not shown. The corresponding elea ments in the two instances are designated by the same reference characters. Instead of the key 8 the circuitis opened and closed in a manner which will presently be brought out. s

The transmitting apparatus may be contained ina casing 49 (Fig. 3) Viithout said casingis a dial 50 fixedly mouuted on a shaft 51 reaching into the casing. The dial maybe provided with a plurality {of holes 52 near its periphery. FiXed on the top of the casing and reaching over. the top of the dial is a stop bracket 53. WVithin thecasing the-shaft 51 carries a spring 54 which is secured to the casing at 55 and serves to resiliently hold the dial in its normal position with the projection 56 on the dial pressing against the stop 53. Loosely mounted on shaft 51 within the case may be provided a disc 57. A spring 58 carried by shaft 51 and secured to said disc at 59 may serve to cause the disc to follow the rotational movements of the shaft 51 and dial 50. Integral with disc 57 is a gear 60,

meshing with a pinion 61, on a shaft 62 which bears in frame 63 and bracket 6et. The shaft 62 may carry fan blades 65 adapted to act as a governor to limit the speed of the disc 57.

Disc 57 may carry contact inserts 66 corresponding to the several holes 52 in the dial 50. Each of these inserts may be electrically connected as at 67 to a collector ring 68. A brush 69 may constantly engage ring 68, while a trolley 70 may serve to ride over the periphery of the disc to successively engage the inserts 66 as the disc rotates.

Loosely mounted on shaft 51 directly under the dial 50 is. shown a hub member 71 provided with an arm 72 which may normally be held by a spring 7 3 secured at. one end to the arm and at the other to a pin 7 4 in the dial, against a pin 75 carried by the dial. Said arm may carry a contact 76 adapted to engage a cooperating contact 77 carried by the dial. In the normal position, the contacts are separated as shown. Additional arms 78 may be provided on hub 71, reaching across the holes 52 as shown.

The receiving apparatus is shown in Fig. 5 and may be the same as that shown in Fig. 2. The corresponding elements in the two figures are given the same reference numerals. The elements of the beacon light and the switch controlling device therefor in so far as they are identical with those shown in Fig. 2, also hear the same reference numerals as in Fig. 2. Interposed between the radio receiver and'the beacon switch-controlling device, however, I have shown means for causing the switclrcontrolling device to be operated only when the proper signal for the particular station has been received.

In the circuit which is closed by contacts '23, 26 are shown two solenoids 80, 81. The

armature 82 of solenoid carries a pawl 83 adapted to act upon a ratchet wheel 84.

- A spring 85 holds the pawl in the position shown, out of contact wit-h ratchet 84:, so that the latter may turn backward without interference from the pawl. The pawl is, however, resiliently pressed as by spring 86 into position to engage and actuate the ratchet. The armature 87 of solenoid 81 may be connected through a spring 88 to a pawl 89 adapted to lock ratchet 84 in position; A spring 90 is adapted to hold said pawl out of contact with the ratchet when the solenoid is not energized. This spring is of course weaker than spring 88 and is overcome by the latter when the armature 87 is in its inner position as shown. The armature 87 may be connected to a dash pot 91 adapted to hold pawl 89 in an operative position fora short time after the solenoid 81 has become deenergized.

On the shaft 92 with ratchet S t is shown a disc 93 provided with a contact insert 9 1 electrically connected to a collector ring 95.

A brush 96 engages said ring and a trolley 97 rides over the periphery of the disc and is adapted to engage contact 94 to close a circuit through the source 2 1 and the solenoid 25. "With the exception of a dash pot 98 connected to the switch arm 28, the switch-controlling apparatus may be the same as in Fig. 2. The function of the dash pot is to clelay the action of solenoid 25 so that the switch 2830 will not be closed in responseto short periods of energizat-ion of the solennoid. Shaft 92 may be provided with a sprin 99 connected'at one end to a relatively fixed member 100 to normally hold the parts in of? position with the projection 101' on disc 93 resting against a relatively fixed stop 102, and to return the parts to such position when the ratchet 84 is released by pawls 83 89.

The position of contact 94 is such that it will engage trolley 97 after pawl 83 has twice engaged ratchet s4 and turned the same two notches. lVhen this takes place, the solenoid 25 will become energized, but will not close switch 28-30, unless the parts are maintained in this position long enough to overcome the action of the dash pot 98.

Fig. 6 shows a disc 93 having its contact 94: so positioned that it will reach the trolley 97 after the ratchet 8 has been turned three notches, while Fig. 7 shows the contact 94/ as adapted to reach the trolley 97 when the ratchet has beenturned four notches. The discs 93,93, 3 may be employed at different stations. Thus, any desired number of discs having their inserts differently positioned may be employed for controlling an equal number of stations.

The operation is as follows:

The aviator desiring to light the beacon at a station which may be designated station 2 inserts his finger in the hole in dial 550 which is also designated 2 and turns the dial until his finger reaches the stop 53. He then holds the dial. in this position for a short time representing the length of time that it takes to overcome'the action of the dash pot 98.

The pressure of the finger will first rotate hub 71 and close contacts 7 6,. 77. The rotation of dial 50 and shaft 51 will, through the connection of spring 59, cause disc 57 to follow, bringing the first and then the second of contacts 66 into engagement with the trolley 70. The closing of contacts 76, 77 and 66, 70 will close the sending circuit from battery 1 through conductor 108, brush 69. ring 68, contact 66, trolley 70, conductor 104, contacts 7 7 76, conductor 105 and back through the elements of the transmitter as heretofore pointed out. After holding the dial for a short time it may be released, whereupon contacts 76, 77 will open and the dial 50 and disc 57 will be returned by spring 5 1 to their normal positions; The lost motion connection between the shaft 51 and disc 57 through spring 58 and the governor 65 will result. in a somewhat unifori'n rotation of the contact disc 57 at a predetermined speed. Eachtime the circuit is closed an impulse will be transmitted and will be received by the apparatus at the several stations. disc 93 will he stepped around until contact 94 engages trolley 97. The parts being held in this position long enough to overcome the dash pct 98, will cause switch 2830 to be closed and also contacts 31, 32. Thus the beacon will belighted and wheel will be set in motion so that switch 28-30 can not'again open until said wheel has completed that the latter will remain in engagement with ratchet 84 holding it in the position to which it was moved until the next impulse causes pawl 83 to again grip the ratchet to turn it another notch. When the dial 50 has been held long enough to cause the switch ZS-30 to be closed, and is then released, solewill take place.

shall be able to brin f into operation the lights noids 80, 81 again become deenergized.

. Pawl 83 will return to off position and spring 90 will ,sgradually overcome the action of dash pot 9i and disengage pawl 89 from ratchet 84;, whereupon the spring 99 will return. the parts to their normal positions. It will be seen that pawl 83 in off position is out of the path of the teeth of the ratchet 84.

It will now be seen that the beacon station having the disc 93 (Fig. 5) is responsive to a code signal represented by one short andone long impulse, or in other words, a dot and a dash, and that the proper impulses may be produced by inserting the finger in the hole in dial designated 2. vThe code to which a station employing the disc in F 6 on the other hand would be two dots and a dash and that of a station employing the disc in Fig.

7 would be three dots and a dash.

When the dial50 is released and returns to its normal position the spring 78 will separate contacts 76, 77, so that as the contacts 66 on disc 57 successively engage trolley while returning, the transmitting circuit will not be closed and no unnecessary operation of the transmitter or any of the receiving apparatus As the aviator nears which he is to land, it is desirable that he of the field-adapted to serve as a in landing The arrangement of these landing lights upon' the field forms no part of the present invention and therefore will not be shown'here; my object being simply to provide means whereby these lights may be lighted from an aeroplane. For this pur e so,

each landing field may be provided with one The the aviation field at Fig. 5. The field floodlights may be connectv ed to the supply lines e6, 17 as shown in Fig. 9. The closing of switch-'2830 will serve to close the circuit of the lights in the same manner in which it closes the circuits of the several beacons. In Fig. 8 T have shown a contact disc 93 having an insert 94 so positioned as to require ten strokes of the pawl 83 to'bring it into contact with trolley 97. To effect this, the aviator will insert his finger in the hole marked 10 on the dial 50 and turn to stop 53, holding it in this position to overcome the dash pot 98. The code for the landing field lights then, is nine dots and a dash.

Each landing field may have its own code,

or if the fields are widely separated so that impulses transmitted near one field will not affect the instruments at the others, all may be controlled by the sa 1e code. Thus, should the aviator be forced to make a landing on account of engine or other trouble, he can transmit the landing or position 10 code and thereby lightup the nearest landing field. When separate codes are assigned to each field, the aviator will transmit the code of the nearest field when forced to land.

In order. that an aviator may ascertain or verify-his position from time to time, the

signals may have distinctive characteristics by which they may be recognized. 'To this end, the reflector 45 in Fig. 2 is shown as tilted to one side and mounted on a vertical shaft 106 provided with a worm wheel 107 meshing with a worm 108 onthe shaft 109 of a motor 110. The motor will thus serve to rotate the reflector about a vertical axis and cause the lightbeam to described a circle in the sky. The beam will appearfrom a distance to be tilting from side to side. Beacons of this characteristicare more specifically set forthin my aforesaid copending application for aviation beacons. The severalbeacons may have different periods of rotation, so that as observed the beams will oscillate at diiferent speeds. Also, some of the beams may osc-illat'ethrough wider angles. Motor 110'may be connected through conductors 111, 112 through source 42 to contacts 31,. 32 so as to be brought into action Whenever the beacon is lighted. p l

In'accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, totogether with the apparatus, which I now consider to represent the best'embodim'ent thereof, but I desire to have it understood that the interfering with the moregeneral results outlined, and the invention extends to such use.

Having herein described my invention what I claim and desire to secure by Letters Patent is:

1. In a beacon system for aircraft, the combination with an aircraft, of a wave impulse sending instrument on the aircraft, a beacon and a receiver for controlling said beacon and adapted to be placed in operation by said sending instrument.

2. In a directing system for aircraft, the combination with an aircraft, of an instrument for sending suitable Wave impulses on the aircraft, a plurality of signals adapted to be placed along the course of the craft and suitable impulse receivers for the signals adapted to set the signals into operation upon approach of the aircraft.

3. In a beacon system for aircraft, the combination with the aircraft, of a radio sending instrument mounted thereon and adapted to transmit signals of variable characteristics, a plurality of beacons, a radio receiver for each beacon set to respond to signals of predetermined characteristics, and means controlled by said receivers for effecting the operation of its beacon.

4. The method of assisting aviators when flying at night which consists in providing at a landing field along the course flood lamps for illuminating the field and setting said lamps into operation by the transmission'of a suitable impulse signal from the aircraft.

5. The method of assisting aviators when flying at night which consists in providing at a landing field along the course, a beacon and a flood lamp, setting said beacon automatically into operation on approach of the aircraft and setting said flood lamp into operation at the will of the aviator.

6. In combination, an aircraft, a radio transmitter adapted to be carried by said aircraft, a radio receiver adapted to respond to impulses produced by said transmitter, a signal for directing the craft, and means controlled by said receiver to cause said signal to become operative.

7. In combination, a plurality of beacons, impulse receiving apparatus for controlling each beacon, an impulse transmitter adapted to be carried by an aircraft and adapted to produce a continuous oscillation of predetermined characteristics for controlling each receiving apparatus when Within predetermined distance thereof.

8. In combination, a receiver adapted to respond to impulses of predetermined characteristics, a switch, means controlled by said receiver for causing said switch to be closed I during the period that said receiver is responding to said impulses, means for opening said switch when not acted upon by said first mentioned means and for holding the same normally opened, and a navigation aid controlled b said switch.

9. In com ination, a disturbance detecting means, a beacon, means for causing oscillation of the beam produced by said beacon, and means controlled by said firstnamed means for starting said beacon and for rendering said oscillation producing means operative.

10. In combination, a wave impulse receiver, a beacon, means controlled by said receiver for lighting said beacon, timing means for controlling the length of time said beacon is lighted, and means also controlled by said receiver for rendering said timing means operative.

11. In combination, an aircraft, a plurality of signals of distinguishable characteristics, radio receiving apparatus for controlling each signal, a radio transmitter adapted to be carried by said aircraft and adapted to produce a continuous oscillation of predetermined characteristics for controlling each receiving apparatus when Within predetermined distance thereof.

12. The method of assisting aviators when flying at night which consists in providing at a landing field along the course flood lamps for illuminating the field and setting said lamps into operation by the transmis sion of Wave impulses sent out by the aircraft.

13. The method of assisting aviators when flying under conditions of low, or absence of, visibility, which consists in providing means located upon the plane for setting automatically into operation, on approach of the plane, and at the will of the aviator, useful means for facilitating landing or continued flight.

14. In an automatic lighting system for landing fields, the combination with wave impulse-producing means on the aircraft, of flood lights, a receiving instrument at the port responsive to reception of impulses from the aircraft of predetermined characteris tics, and means controlled thereby for lighting said lights.

15. In an automatic lighting system for landing fields, the combination with Wave impulse-producing means on the aircraft, of flood lights, a receiving instrument at the port responsive to reception of impulses from the aircraft of predetermined characterisv broughtinto operation when said means is Within a predetermined distance'thereof, and means controlledv by said instrument for lighting said system. i 57 17. In a beacon system for aviators, the combination with air beacons and means on the aircraft producing a continuous disturbance, of a receiving instrument at each beacon attuned to such disturbance and'brougbt 0, into action on increase in volume of the received disturbance beyond a predetermined magnitude, and means controlled by said instrument for rendering said beacon efiiective. 18. In a beacon system for aviators, the combination with air beacons and means on the aircraft producing a continuous disturbance, of a receiving instrument at each beacon attuned to such disturbance and brought, into action on increase in volume of the re ceived disturbance beyond a predetermined magnitude,and means controlled by said instrument for rendering said beacon efiective for quenching said beacon on decrease in such magnitude. I 19. In a system for assisting aerial navigation, normally inoperative signalling means located at predetermined points, such as landing field, for facilitating landing or continued flight, means on the aircraft produc- I p ing a disturbance, and a receiving device at said predetermined points responsive to said disturbance for rendering said signalling means operative.

20. In combination, an aircraft, a trans mitter for sending suitable Wave impulses adapted to be carried by said aircraft, a suitable impulse receiver adapted to respond to impulses produced by said transmitter, a navigation aid for the craft,and means controlled by said receiver to cause said aid'to become operative.

In testimony whereof I have affixed my signature.

ELMER A. SPERRY. 

